Metal surface primer

ABSTRACT

A deck primer for use with nonslip deck coatings of the chemically cured-resin type comprising a mixture of Formula No. 117 wash primer (as set forth in Military Specification MIL-D23003(SHIPS) and its Amendment 2) and a specific, moisture-cured, polyurethane resin, in the ratio of 5:4 parts by volume, respectively.

United States Patent Arthur J. Berger Croton-on-Hudson;

Albert W. Clzek, .lr., Valley Stream; Raymond J. Simeon, Mlddleburg, allof N.Y.

July 31, 1969 Oct. 26, 197 l The United States of America as representedby the Secretary of the Navy Inventors Appl. No. Filed Patented AssigneeMETAL SURFACE PRIMER 4 Claims, 1 Drawing Fig.

U.S. Cl l48/6.l6, 117/75, 260/2922 TN Int. Cl C23! 7/10 Field of Searchl l7/16l KP, 75; 260/292 TN, 29.2 M, 29.6 M; l48/6.16, 6.2, 6.15

[56] References Cited FOREIGN PATENTS l,l47,820 4/1963 Germany PrimaryExaminer-Ralph S. Kendall Attorneys- Louis A. Miller, Louis B. Applebaumand Philip Schneider ABSTRACT: A deck primer for use with nonslip deckcoatings of the chemically cured-resin type comprising a mixture ofFormula No. l 17 wash primer (as set forth in Military SpecificationMlL-D-23003(SHIPS) and its Amendment 2) and a specific, moisture-cured,polyurethane resin, in the ratio of 5:4 parts by volume, respectively.

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Ra mo/v0 J 6/446 M mip Y METAL SURFACE PRIMER The invention describedherein may be manufactured and used by or for the Government of theUnited States of America for governmental purposes without the paymentof any royalties thereon or therefor.

This invention relates to primers for metal surfaces and especially to atough, thick, adherent, anticorrosive primer for use with nonslip deckcoatings.

Laboratory studies and field reports of the U.S. Navy indicate thedesirability of applying to clean metal surfaces a tough primer as abase for nonslip deck coatings. Three primers are currently specified inMilitary Specification MIL- D-23003 (SHIPS) and its Amendment 2 (Formula117 wash primer; Formula 116, red lead primer; and Formula 84, zincchromate primer) for priming metal deck surfaces prior to theapplication of a nonslip deck coating.

In service, the performance of the nonslip deck coatings is found tovary depending on the type of primer used. In most cases, after thenonslip deck coating has worn away or separated from the primer due topoor adhesion, the metal surface starts to corrode rapidly as the primerwears away due to the low impact resistance and inadequate toughness ofthe latter.

As a result of compatibility studies conducted on two epoxy deckcoatings, it has been recommended that only the Formula 1 l7 wash primerbe used as a basis for Type II (chemically cured resins, such as epoxiesand polyurethanes) coatings of the Military Specification referred toabove. Service reports indicate, however, that although the Type II deckcoatings show the best adhesion to the Formula 1 l7 wash primer, theprimer wears rapidly or is scored readily, allowing corrosion of thesteel deck to occur after the deck coating has been worn away. The causeof the rapid wearing and scoring is attributed to the limited thickness,approximately 0.5 mil, of the primer.

An object of this invention is to provide a primer which produces athicker film having better toughness and abrasion characteristics thanthe Formula No. 1 l7 wash primer.

Another object is to provide a primer which forms a tough, thick,adherent, anticorrosion film for use with all nonslip deck coatings.

The objects and advantages of this invention are provided by adding aspecific moisture-curing, polyurethane resin to the Formula No. 117 washprimer.

Other objects, advantages and novel features of the invention willbecome apparent from the following detailed description of the inventionwhen considered in conjunction with the accompanying drawing wherein:

The single FIG. is a cross-sectional view of a nonslip deck coatingapplied to the new primer which is laid on a steel substrate.

The new primer is made by adding a moisture-cured, polyurethane resin tothe Formula No. 1 l7 wash primer.

Pounds per Galltns per I gallons I00 gallons of mixed of mixed materialmaterial lngredients of resin component (80 gallons):

Polyvinyl-butyral resin (Note I) 56 6.10 Zinc chromate (insoluble type)(Note 2) 54 L78 Magnesium-silicate (Type A or B of SpecificationMlL-M-ll73 8 0.34 Lampblack (Specification 'lT-L-70)... 0.6 0.04 Butylalcohol, normal (Spec. 'l'T-B-846). l25 18.48 isopropyl alcohol, 99percent (Notes 3 & 353 53.80 Water L80 Ingredients of acid component (2Phosphoric acid (Class A ofSpec. O-P-3 l3) 28 2.0 Water Z5 3.0 isopropylalcohol, 99 percent (Notes 3 8t 99 15.0

1. The resin shall be a polyvinyl partial butyral resin containing onlypolyvinyl butyral, polyvinyl alcohol, and polyvinyl acetate in themolecule. The resin shall contain 18.0 to 20.0 percent vinyl alcohol,and not more than l.0 percent of vinyl acetate. A 6 percent solution ofthe resin in methanol shall have a viscosity of 12 to 18 centipoises at20 C. The specific gravity of the resin shall be 1.05 to H5. 2. The zincchromate shall be of an insoluble type, showing an analysis of 16 to l9percent CrO and 67 to 72 percent ZnO, and not more than 1 percent watersoluble salts. 3. lsopropyl alcohol, 99 percent shall have a specificgravity of 0.785 to 0.790 at 20l20 C., and a distillation range notgreater than 1.5 C., and this range shall include 823C. 4. Ethyl alcoholconforming to Grade ill of Specification O-E 760 may be substituted forisopropyl alcohol, 99 percent. The isopropyl alcohol (99 percent) andwater in the resin component may be replaced by 375 pounds (55.5)gallons of ethyl alcohol. The isopropyl alcohol (99 percent) in the acidcomponent may be replaced by 102 pounds l5.0 gallons) of ethyl alcohol.The formula for the polyurethane resin is provided in U.S. Pat. No.3,240,618, for Concrete Form Panels," issued to Charles B. Hemmings onMar. l5, 1966. A one can urethane system is prepared by reacting underreflux conditions and under inert atmosphere, a diol or triol or anyother polyhydroxy compound (poiyether polyols, polyester polyols orcastor oil), with toluene diisocyanate in a solvent system. The ratio ofthe isocyanate to polyhydroxy being 21/1. The reaction temperature ismaintained at reflux and the rate of reaction is controlled by checkingthe free NCO of the reaction. The urethane prepared above is formulatedwith solvents to give a 50/50 percent solid content. Antioxidants anddriers are also incorporated to give the final urethane coating. Thecure of this system is effected by atmosphere moisture. The resin can beobtained commercially from the Spencer Kellogg Division ofTextron, inc.under the designation M-50CX The ingredients of the new primer are asfollow:

Butyl alcohol, normal isopropyl alcohol Water Phosphoric aeid Waterisopropyl alcohol 4 M80-50('X polyurethane resin B (acid component) I C(resin component) Parts A and B form the constituents of Formula Parts Aand B form the constituents of Formula N0. N7 wash primer. The mixtureis made by adding Part A to Part C and mixing for abut 1 minute, thenadding Part B and mixing for about 2 minutes more.

The mixture should be made just before it is applied. Application can beaccomplished with a standard paint roller.

Test results indicate that the new primer exhibits superior performanceas a prime for nonslip deck coatings for the following reasons:

a. After a l-hour drying period, a film thickness of 2 mils is obtainedcompared to 0.5 mils for Formula No. 1 17;

b. The thicker film of the new primer is tough and flexible, as shown byimpact resistance tests, and provides excellent corrosion and weatheringresistance. Therefore, it provides prolonged protection of the deckprior to the application of the deck-covering compound;

c. The adhesion of Type ll nonslip deck coatings to the new primer isexcellent.

We claim:

1. A primer for use with nonslip deck coatings of the chemicallycured-resin type comprising five parts by volume of wash primerconsisting of a mixture of polyvinyl butyral resin, zinc chromate,magnesium silicate, lampblack, butyl alcohol normal, isopropyl alcohol,phosphoric acid and water and four parts by volume ofa moisture-curedpolyurethane resin.

2. A primer as in claim I, wherein said polyurethane resin is apolyurethane resin consisting of the reaction produce of a polyhydroxycompound with toluene diisocyanate in a solvent system with antioxidantand drier additives.

3. A primer as in claim 1, wherein four parts by volume of the resincomponent of said wash primer and four parts by volume of saidpolyurethane resin are mixed for about 1 minute and then one part byvolume of the acid component of said wash primer is mixed in for about 2minutes more.

2. A primer as in claim 1, wherein said polyurethane resin is apolyurethane resin consisting of the reaction produce of a polyhydroxycompound with toluene diisocyanate in a solvent system with antioxidantand drier additives.
 3. A primer as in claim 1, wherein four parts byvolume of the resin component of said wash primer and four parts byvolume of said polyurethane resin are mixed for about 1 minute and thenone part by volume of the acid component of said wash primer is mixed infor about 2 minutes more.
 4. A primer as in claim 2, wherein four partsby volume of the resin component of said wash primer and four parts byvolume of said polyurethane resin are mixed for about 1 minute and thenone part by volume of the acid component of said wash primer is mixed infor about 2 minutes.